The following columns will no longer be available starting February 2, 2013:

BudgetLostImpressionShare

ExactMatchImpressionShare

ImpressionShare

QualityLostImpressionShare

We recommend reviewing your report definitions to ensure they are up-to-date with the change. As always, please feel free to ask any questions regarding the client libraries or the AdWords API on our forum or during scheduled office hours. You can also follow the Google Ads Developer page for all Ads-related updates.